1. Field of the Invention
The present invention relates to, an image forming apparatus such as an electrophotographic copying machine, and an electrophotographic printer and the like, and a process cartridge detachable to such an image forming apparatus.
2. Related Background Art
In the past, in electrophotographic image forming apparatuses, such as electrophotographic copying machines, if the apparatus has been used for a long time, replacement of an electrophotographic photosensitive drum, replacement of a developing device, replenishment of toner (developer), cleaning of a charger, replacement of a cleaning contained filled with waste toner and adjustment of the electrophotographic photosensitive drum and therearound, have been required.
Thus, conventionally, in the electrophotographic image forming apparatus using an electrophotographic image forming process, the electrophotographic photosensitive drum and process means acting on the drum are integrally incorporated as a cartridge unit which can detachably be mounted to the electrophotographic image forming apparatus, thereby forming a process cartridge.
According to this system, since the maintenance of the electrophotographic image forming apparatus can be effected by the used himself, operability could be improved considerably. Therefore, such a process cartridge has widely been used in the electrophotographic image forming apparatus.
In such a process cartridge, before the process cartridge is mounted to the electrophotographic image forming apparatus, by pulling a toner seal member out of the process cartridge, an opening portion of a developer container as a developer frame containing toner is opened, so that the toner can be supplied to a developing means, such as a developing roller, provided within a developing container. Further, also in a developing cartridge, a seal member is provided on an opening portion between the developer container and the developing container, which seal member can be removed later.
Further, in such an electrophotographic image forming apparatus, if the toner (developer) becomes insufficient during the image forming operation, since an inconvenience such as reduction of image density or poor image, occurs, normally, a remaining amount of toner within the process cartridge is always monitored so that the toner can be replenished before the inconvenience, such as the reduction of the image density, occurs, so that, if the toner becomes insufficient, such a fact is displayed and warns the user.